This invention relates to keyboards used by an operator for controlling and interacting with a computer, and more specifically, to layouts of keys in desktop keyboards for entering desired inputs to a processor.
Being a desktop product, a conventional personal computer (PC) typically comprises an enclosure which houses electronic boards containing one or more of the main microprocessor chips, a video display terminal (VDT) and a keyboard. Standard keyboards provided with PC products from such manufacturers as IBM and Wang Laboratories, INC. (WLI) have alphanumeric keys which are sized for use by one or more fingers of an operator (PC user). As is well known, the layout of the alphabetical keys is in the so-called QWERTY format which was developed for the typewriter. This arrangement permits relatively fast generation of inputs by many operators, especially those who have ten-finger touch typing skills. However, the finger-actuable keys have certain minimum keypad dimensions which are consistent with human factors design considerations so that the standard keyboard generally has a certain overall size or footprint on the desktop.
With the inclusion and popularity of other interface devices such as a tablet for providing graphical inputs to a PC, the operator's desk becomes more crowded and desktop space becomes very important. For those applications where use of the graphical tablet predominates, a smaller keyboard is very desirable.
Although small alphanumeric keyboards have existed for hand-held programmable calculators, those designs have not been widely adapted for PC use. Having a full set of alphabetic and numeric keys, the keyboards for such calculators typically have very small keypad areas because each calculator is designed to be comfortably held by one hand while the other hand is used for keystroking. There are other calculators with keys so small that a stylus such as a pen is used for key actuation because the operator's finger is to broad for accurate key selection. In other words, the keys are so close together that keystroking by one finger is difficult without making erroneous and unwanted multiple actuations of nearby keys.
Programmable and other calculators are arranged so that key actuations must be made one after another in a sequential order only. This arrangement avoids the problems attendant with generating commands and inputs that require simultaneous keystrokes of two or more small keys. As a result, these calculators typically have the letter keys in alphabetical order and not in the QWERTY order for ease of operator selection. However, strictly sequential keystroking is not desirable for PC products because it would require a change of the habits and training of many operators. Specifically, it is well known that generating capital letters or special function commands can be accomplished by actuating the conventional SHIFT key simultaneously with an alphabetical or other key, respectively. For two-handed keystroking, such SHIFT key use is well accepted because many operators use touch typing techniques borrowed from standard typewriter procedures.
In addition, there are other well known PC commands which require more than two simultaneous keystrokes. The so-called warm restart command is an example of a triple simultaneous keystroke procedure. In the IBM PC product, that command is generated by the simultaneous actuation of the CONTROL, ALTERNATE and DELETE keys. In the WLI PC product, that command is produced by keystroking simultaneously the 2nd (or ALTERNATE), COMMAND and CANCEL keys.
Accordingly, there is a need for an improved PC keyboard which has a smaller footprint than standard keyboards in order to reduce the amount space used on a desktop. Moreover, the improved keyboard should offer the same general keystroke procedure and functions as those used for standard PC keyboards and typewriters.